Drilling boreholes by rotary drilling usually involves use of a drill string with a drill bit at the distal end, and a motor at the rig end. The drill string is conventionally made up of many drillpipe sections which are connected together by threaded box and pin connections. The drillpipe sections are typically 9.5–13.1 meters long, are relatively heavy, and require careful handling.
For storing and transporting drillpipe and other tubulars it is known to stack tubular lengths in cuboid bundles. The bundles are formed using perhaps four U-frames, with spacers being located between the arms of the U-frames and having upper and lower faces profiled to co-operate with tubular lengths of a particular diameter. The U-frames are spaced along the bundle and the bundle is lifted by slings or the like coupled to the U-frames. Accordingly, the spacers must be selected to suit the particular drillpipe dimensions, such that it is necessary for drillpipe suppliers and shippers to retain an extensive inventory of spacers.
An improved drillpipe packaging apparatus has been developed, and is described in International Patent Application PCT/GB00/00176. This improved apparatus comprises a pair of U-frames connected by spacers, on which are located deformable elastomeric packing members. In use, the elongate members to be packed are separated by the deformable members, which will deform to grip the elongate members securely. As the packaging members are deformable, the members may be used to package a variety of sizes of drillpipes, so obviating the need for suppliers and shippers to retain a range of packaging members. In order to bring about secure engagement of the drillpipes and packaging members, the apparatus further comprises a retaining arrangement to urge the stack of drillpipes and packaging members together. However, currently-known retaining arrangements are often unwieldy and may be difficult to fix correctly; further, existing retaining arrangements do not avoid the possibility that pressure may be applied unevenly to the stack of drillpipes, as a retaining arrangement on each side of each U-frame must be adjusted by hand separately.
It is among the objects of embodiments of the present invention to obviate or alleviate these and other disadvantages of the prior art.